On Mon, Dec 15, 2008 at 02:08:16PM +0200, Jani Nikula wrote: > Add new function omap_update_gpio_switch() to support dynamically > changing the GPIO switch notify callback functions and debounce > timeouts. Why do they need to be changed? GPIO switches related to the board schematics, which do not hopefully change dynamically. > + spin_lock_irqsave(&sw->lock, flags); > if (state) > timeout = sw->debounce_rising; > else > timeout = sw->debounce_falling; > + spin_unlock_irqrestore(&sw->lock, flags); What's the point of this? The above read can be consider an atomic operation. > + spin_lock_irqsave(&sw->lock, flags); > + notify = sw->notify; > + notify_data = sw->notify_data; > + spin_unlock_irqrestore(&sw->lock, flags); > + > + if (notify != NULL) > + notify(notify_data, state); What if omap_update_gpio_switch() is called just before the check for notify != NULL from another (hypothetical =)) CPU? Then you end up with the function completing, but still having the old notify callback called with old notify_data. Cheers, Juha -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
